Southern Pine DNA Transfer Patent Approval

A US Patent application claiming biotechnology methods was submitted based on original research and development carried out for a process to stably transfer DNA into several species of Southern pine trees. This process of stable transfer of DNA into cells is called "gene transfer" or transformation. The method involved physical treatment and handling of the DNA molecules and specific processes to allow the DNA to enter the target pine cells. The target pine cells were cultured in vitro using a patented process in which a distinct phase of cell growth was identified as being critical for success in transferring DNA in such a way that the resulting pine plants contained the foreign DNA in each cell and the genes conveyed the desired traits to the plants.

Initial application to the US patent office resulted in a rejection of several critical claims based on two main arguments.

• Objection #1 : A patented process for transfer of DNA into Southern pine cells was already issued that used the same technique for moving DNA into the cells.
• Objection #2 : A patented process for transfer of DNA into Spruce cells was already issued that used a similar cell culture process to prepare cells for DNA transfer.

An argument was prepared to the patent examiner showing that the two major objections to granting the patent were not valid for denial of the claimed methods.

For objection #1, an argument was made that the issued patent did not effectively teach the claimed methods. Following the methods taught in the patent, the claimed result of a stably transformed culture that lead to production of a pine tree could not be obtained. Several points of evidence were obtained to support this argument. A leading university researcher employed the claimed methods for several years in an attempt to produce stably transformed pine trees with only partially successful results. The trees obtained by this researcher indeed contained the introduced DNA but not in every cell of the resulting trees but rather only a subset of the cells contained the DNA. More compelling evidence came from examination of the publication records of the inventors revealed that the methods covered in the patent were not effective in obtaining the desired outcome. The evidence for the ineffectiveness of the claims was based on repeated publications after issuance of the patent in which the inventors indicated the critical need in the industry for an effective method to develop an effective method for DNA transfer into Southern pine trees. The inventors also actively recruited staff scientists after issuance of the patent to develop an effective method for transformation of pine trees. The scientist recruited abandoned the claimed methods in attempting to develop an effective technique. Further, in personal communication with the inventors, they admitted that the patented techniques were not effective in achieving the claimed outcome.

For objection #2, a detailed analysis of the claims of both patents was made with regard to the cell culture method. Both methods were addressing the clonal multiplication of conifer plantlets from an immature embryo source tissue. The pre-existing patent gave a method for multiplication of spruce plantlets (genus Picea) and the patent in dispute taught methods specific to pine plantlets (species Pinus). However both of these techniques were very similar in the techniques used and the stages of development described. It was successfully argued with the US patent office that while the methods of cell culture are very similar in both patents, the critical stage of development for pine cells required for successful DNA transfer was substantially different than the critical stage for spruce. Specifically, the spruce claims taught the use of a developmental stage that was later than the required developmental stage for pine cell cultures. This was substantiated by examination of publications by the inventor on the spruce patent where it was reported that the specific stages of development that were effective for pine were not effective for spruce. Furthermore, if the methods taught for gene transfer in spruce cells were used for pine cultures there was no evidence of stable gene transfer in the pine plantlets.

The result of this argument to the US patent office was allowance of all of the disputed claims and issuance of a US patent.

To see the resume of the expert associated with this case study, see the link below.